Liquid crystal displays (LCDs) have advantages such as low radiation, small size, and low power consumption, and are gradually taking place of traditional cathode ray tube displays (CRTs) and have been widely used in products such as laptops, personal digital assistants (PDA), flat TVs and mobile phones.
A liquid crystal display includes a display panel and a backlight module. A backlight module is a module providing a light source for a liquid crystal display product, and is usually disposed below a display panel to provide light that is uniformly diffused and of a definite brightness to the display panel. According to different voltages of pixel electrodes on the display panel, color images with different brightness, of different colors, and in different gray scales can be formed.
A backlight module with a light source disposed on a side face is an edge lighting type backlight module. In an edge lighting type backlight module, light generated by a light source (linear light source) enters a light guide plate, the linear light source is converted to a surface light source by the light guide plate and then is emitted out, then passes through a lower polarizer and is converted into a linear polarized light and reaches the display panel. However, in a known edge lighting type backlight module, the lower polarizer only allows linear polarized light to pass through, and light can not pass through the lower polarizer cannot be used.